/*

Copyright (c) 2003-2020, Arvid Norberg
Copyright (c) 2015, Mike Tzou
Copyright (c) 2016, 2018-2019, Alden Torres
Copyright (c) 2016, Andrei Kurushin
Copyright (c) 2017, AllSeeingEyeTolledEweSew
Copyright (c) 2017-2018, Steven Siloti
Copyright (c) 2019, Pavel Pimenov
All rights reserved.

You may use, distribute and modify this code under the terms of the BSD license,
see LICENSE file.
*/

#include <cstdio> // for snprintf
#include <cstdlib> // for atoi
#include <cstring>
#include <utility>
#include <deque>
#include <fstream>
#include <regex>
#include <algorithm> // for min()/max()

#include "libtorrent/config.hpp"

#ifdef TORRENT_WINDOWS
#include <direct.h> // for _mkdir and _getcwd
#include <sys/types.h> // for _stat
#include <sys/stat.h>
#endif

#ifdef TORRENT_UTP_LOG_ENABLE
#include "libtorrent/utp_stream.hpp"
#endif

#include "libtorrent/torrent_info.hpp"
#include "libtorrent/announce_entry.hpp"
#include "libtorrent/entry.hpp"
#include "libtorrent/bencode.hpp"
#include "libtorrent/session.hpp"
#include "libtorrent/session_params.hpp"
#include "libtorrent/identify_client.hpp"
#include "libtorrent/alert_types.hpp"
#include "libtorrent/ip_filter.hpp"
#include "libtorrent/magnet_uri.hpp"
#include "libtorrent/peer_info.hpp"
#include "libtorrent/bdecode.hpp"
#include "libtorrent/add_torrent_params.hpp"
#include "libtorrent/time.hpp"
#include "libtorrent/read_resume_data.hpp"
#include "libtorrent/write_resume_data.hpp"
#include "libtorrent/string_view.hpp"
#include "libtorrent/disk_interface.hpp" // for open_file_state
#include "libtorrent/disabled_disk_io.hpp" // for disabled_disk_io_constructor

#include "torrent_view.hpp"
#include "session_view.hpp"
#include "print.hpp"


#ifdef _WIN32

#include <windows.h>
#include <conio.h>

#else

#include <termios.h>
#include <sys/ioctl.h>
#include <csignal>
#include <utility>
#include <dirent.h>

#endif

namespace {

using lt::total_milliseconds;
using lt::alert;
using lt::piece_index_t;
using lt::file_index_t;
using lt::torrent_handle;
using lt::add_torrent_params;
using lt::total_seconds;
using lt::torrent_flags_t;
using lt::seconds;
using lt::operator "" _sv;
using lt::address_v4;
using lt::address_v6;
using lt::make_address_v6;
using lt::make_address_v4;
using lt::make_address;

using std::chrono::duration_cast;
using std::stoi;

#ifdef _WIN32

bool sleep_and_input(int* c, lt::time_duration const sleep)
{
	for (int i = 0; i < 2; ++i)
	{
		if (_kbhit())
		{
			*c = _getch();
			return true;
		}
		std::this_thread::sleep_for(sleep / 2);
	}
	return false;
}

#else

struct set_keypress
{
	enum terminal_mode {
		echo = 1,
		canonical = 2
	};

	explicit set_keypress(std::uint8_t const mode = 0)
	{
		using ul = unsigned long;

		termios new_settings;
		tcgetattr(0, &stored_settings);
		new_settings = stored_settings;
		// Disable canonical mode, and set buffer size to 1 byte
		// and disable echo
		if (mode & echo) new_settings.c_lflag |= ECHO;
		else new_settings.c_lflag &= ul(~ECHO);

		if (mode & canonical) new_settings.c_lflag |= ICANON;
		else new_settings.c_lflag &= ul(~ICANON);

		new_settings.c_cc[VTIME] = 0;
		new_settings.c_cc[VMIN] = 1;
		tcsetattr(0,TCSANOW,&new_settings);
	}
	~set_keypress() { tcsetattr(0, TCSANOW, &stored_settings); }
private:
	termios stored_settings;
};

bool sleep_and_input(int* c, lt::time_duration const sleep)
{
	lt::time_point const done = lt::clock_type::now() + sleep;
	int ret = 0;
retry:
	fd_set set;
	FD_ZERO(&set);
	FD_SET(0, &set);
	auto const delay = total_milliseconds(done - lt::clock_type::now());
	timeval tv = {int(delay / 1000), int((delay % 1000) * 1000) };
	ret = select(1, &set, nullptr, nullptr, &tv);
	if (ret > 0)
	{
		*c = getc(stdin);
		return true;
	}
	if (errno == EINTR)
	{
		if (lt::clock_type::now() < done)
			goto retry;
		return false;
	}

	if (ret < 0 && errno != 0 && errno != ETIMEDOUT)
	{
		std::fprintf(stderr, "select failed: %s\n", strerror(errno));
		std::this_thread::sleep_for(lt::milliseconds(500));
	}

	return false;
}

#endif

bool print_trackers = false;
bool print_peers = false;
bool print_connecting_peers = false;
bool print_log = false;
bool print_downloads = false;
bool print_matrix = false;
bool print_file_progress = false;
bool show_pad_files = false;
bool show_dht_status = false;

bool print_ip = true;
bool print_local_ip = false;
bool print_timers = false;
bool print_block = false;
bool print_fails = false;
bool print_send_bufs = true;
bool print_disk_stats = false;

// the number of times we've asked to save resume data
// without having received a response (successful or failure)
int num_outstanding_resume_data = 0;

#ifndef TORRENT_DISABLE_DHT
std::vector<lt::dht_lookup> dht_active_requests;
std::vector<lt::dht_routing_bucket> dht_routing_table;
#endif

std::string to_hex(lt::sha1_hash const& s)
{
	std::stringstream ret;
	ret << s;
	return ret.str();
}

bool load_file(std::string const& filename, std::vector<char>& v
	, int limit = 8000000)
{
	std::fstream f(filename, std::ios_base::in | std::ios_base::binary);
	f.seekg(0, std::ios_base::end);
	auto const s = f.tellg();
	if (s > limit || s < 0) return false;
	f.seekg(0, std::ios_base::beg);
	v.resize(static_cast<std::size_t>(s));
	if (s == std::fstream::pos_type(0)) return !f.fail();
	f.read(v.data(), int(v.size()));
	return !f.fail();
}

bool is_absolute_path(std::string const& f)
{
	if (f.empty()) return false;
#if defined(TORRENT_WINDOWS) || defined(TORRENT_OS2)
	int i = 0;
	// match the xx:\ or xx:/ form
	while (f[i] && strchr("abcdefghijklmnopqrstuvxyz", f[i])) ++i;
	if (i < int(f.size()-1) && f[i] == ':' && (f[i+1] == '\\' || f[i+1] == '/'))
		return true;

	// match the \\ form
	if (int(f.size()) >= 2 && f[0] == '\\' && f[1] == '\\')
		return true;
	return false;
#else
	if (f[0] == '/') return true;
	return false;
#endif
}

std::string path_append(std::string const& lhs, std::string const& rhs)
{
	if (lhs.empty() || lhs == ".") return rhs;
	if (rhs.empty() || rhs == ".") return lhs;

#if defined(TORRENT_WINDOWS) || defined(TORRENT_OS2)
#define TORRENT_SEPARATOR "\\"
	bool need_sep = lhs[lhs.size()-1] != '\\' && lhs[lhs.size()-1] != '/';
#else
#define TORRENT_SEPARATOR "/"
	bool need_sep = lhs[lhs.size()-1] != '/';
#endif
	return lhs + (need_sep?TORRENT_SEPARATOR:"") + rhs;
}

std::string make_absolute_path(std::string const& p)
{
	if (is_absolute_path(p)) return p;
	std::string ret;
#if defined TORRENT_WINDOWS
	char* cwd = ::_getcwd(nullptr, 0);
	ret = path_append(cwd, p);
	std::free(cwd);
#else
	char* cwd = ::getcwd(nullptr, 0);
	ret = path_append(cwd, p);
	std::free(cwd);
#endif
	return ret;
}

std::string print_endpoint(lt::tcp::endpoint const& ep)
{
	using namespace lt;
	char buf[200];
	address const& addr = ep.address();
	if (addr.is_v6())
		std::snprintf(buf, sizeof(buf), "[%s]:%d", addr.to_string().c_str(), ep.port());
	else
		std::snprintf(buf, sizeof(buf), "%s:%d", addr.to_string().c_str(), ep.port());
	return buf;
}

using lt::torrent_status;

FILE* g_log_file = nullptr;

int peer_index(lt::tcp::endpoint addr, std::vector<lt::peer_info> const& peers)
{
	using namespace lt;
	auto i = std::find_if(peers.begin(), peers.end()
		, [&addr](peer_info const& pi) { return pi.ip == addr; });
	if (i == peers.end()) return -1;

	return int(i - peers.begin());
}

// returns the number of lines printed
int print_peer_info(std::string& out
	, std::vector<lt::peer_info> const& peers, int max_lines)
{
	using namespace lt;
	int pos = 0;
	if (print_ip) out += "IP                             ";
	if (print_local_ip) out += "local IP                       ";
	out += "progress        down     (total | peak   )  up      (total | peak   ) sent-req tmo bsy rcv flags         dn  up  source  ";
	if (print_fails) out += "fail hshf ";
	if (print_send_bufs) out += "rq sndb (recvb |alloc | wmrk ) q-bytes ";
	if (print_timers) out += "inactive wait timeout q-time ";
	out += "  v disk ^    rtt  ";
	if (print_block) out += "block-progress ";
	out += "client \x1b[K\n";
	++pos;

	char str[500];
	for (std::vector<peer_info>::const_iterator i = peers.begin();
		i != peers.end(); ++i)
	{
		if ((i->flags & (peer_info::handshake | peer_info::connecting)
			&& !print_connecting_peers))
		{
			continue;
		}

		if (print_ip)
		{
			std::snprintf(str, sizeof(str), "%-30s ", (::print_endpoint(i->ip) +
				(i->flags & peer_info::utp_socket ? " [uTP]" : "") +
				(i->flags & peer_info::i2p_socket ? " [i2p]" : "")
				).c_str());
			out += str;
		}
		if (print_local_ip)
		{
			std::snprintf(str, sizeof(str), "%-30s ", ::print_endpoint(i->local_endpoint).c_str());
			out += str;
		}

		char temp[10];
		std::snprintf(temp, sizeof(temp), "%d/%d"
			, i->download_queue_length
			, i->target_dl_queue_length);
		temp[7] = 0;

		char peer_progress[10];
		std::snprintf(peer_progress, sizeof(peer_progress), "%.1f%%", i->progress_ppm / 10000.0);
		std::snprintf(str, sizeof(str)
			, "%s %s%s (%s|%s) %s%s (%s|%s) %s%7s %4d%4d%4d %s%s%s%s%s%s%s%s%s%s%s%s%s %s%s%s %s%s%s %s%s%s%s%s%s "
			, progress_bar(i->progress_ppm / 1000, 15, col_green, '#', '-', peer_progress).c_str()
			, esc("32"), add_suffix(i->down_speed, "/s").c_str()
			, add_suffix(i->total_download).c_str(), add_suffix(i->download_rate_peak, "/s").c_str()
			, esc("31"), add_suffix(i->up_speed, "/s").c_str(), add_suffix(i->total_upload).c_str()
			, add_suffix(i->upload_rate_peak, "/s").c_str(), esc("0")

			, temp // sent requests and target number of outstanding reqs.
			, i->timed_out_requests
			, i->busy_requests
			, i->upload_queue_length

			, color("I", (i->flags & peer_info::interesting)?col_white:col_blue).c_str()
			, color("C", (i->flags & peer_info::choked)?col_white:col_blue).c_str()
			, color("i", (i->flags & peer_info::remote_interested)?col_white:col_blue).c_str()
			, color("c", (i->flags & peer_info::remote_choked)?col_white:col_blue).c_str()
			, color("x", (i->flags & peer_info::supports_extensions)?col_white:col_blue).c_str()
			, color("o", (i->flags & peer_info::local_connection)?col_white:col_blue).c_str()
			, color("p", (i->flags & peer_info::on_parole)?col_white:col_blue).c_str()
			, color("O", (i->flags & peer_info::optimistic_unchoke)?col_white:col_blue).c_str()
			, color("S", (i->flags & peer_info::snubbed)?col_white:col_blue).c_str()
			, color("U", (i->flags & peer_info::upload_only)?col_white:col_blue).c_str()
			, color("e", (i->flags & peer_info::endgame_mode)?col_white:col_blue).c_str()
			, color("E", (i->flags & peer_info::rc4_encrypted)?col_white:(i->flags & peer_info::plaintext_encrypted)?col_cyan:col_blue).c_str()
			, color("h", (i->flags & peer_info::holepunched)?col_white:col_blue).c_str()

			, color("d", (i->read_state & peer_info::bw_disk)?col_white:col_blue).c_str()
			, color("l", (i->read_state & peer_info::bw_limit)?col_white:col_blue).c_str()
			, color("n", (i->read_state & peer_info::bw_network)?col_white:col_blue).c_str()
			, color("d", (i->write_state & peer_info::bw_disk)?col_white:col_blue).c_str()
			, color("l", (i->write_state & peer_info::bw_limit)?col_white:col_blue).c_str()
			, color("n", (i->write_state & peer_info::bw_network)?col_white:col_blue).c_str()

			, color("t", (i->source & peer_info::tracker)?col_white:col_blue).c_str()
			, color("p", (i->source & peer_info::pex)?col_white:col_blue).c_str()
			, color("d", (i->source & peer_info::dht)?col_white:col_blue).c_str()
			, color("l", (i->source & peer_info::lsd)?col_white:col_blue).c_str()
			, color("r", (i->source & peer_info::resume_data)?col_white:col_blue).c_str()
			, color("i", (i->source & peer_info::incoming)?col_white:col_blue).c_str());
		out += str;

		if (print_fails)
		{
			std::snprintf(str, sizeof(str), "%4d %4d "
				, i->failcount, i->num_hashfails);
			out += str;
		}
		if (print_send_bufs)
		{
			std::snprintf(str, sizeof(str), "%2d %6d %6d|%6d|%6d%5dkB "
				, i->requests_in_buffer, i->used_send_buffer
				, i->used_receive_buffer
				, i->receive_buffer_size
				, i->receive_buffer_watermark
				, i->queue_bytes / 1000);
			out += str;
		}
		if (print_timers)
		{
			char req_timeout[20] = "-";
			// timeout is only meaningful if there is at least one outstanding
			// request to the peer
			if (i->download_queue_length > 0)
				std::snprintf(req_timeout, sizeof(req_timeout), "%d", i->request_timeout);

			std::snprintf(str, sizeof(str), "%8d %4d %7s %6d "
				, int(total_seconds(i->last_active))
				, int(total_seconds(i->last_request))
				, req_timeout
				, int(total_seconds(i->download_queue_time)));
			out += str;
		}
		std::snprintf(str, sizeof(str), "%s|%s %5d "
			, add_suffix(i->pending_disk_bytes).c_str()
			, add_suffix(i->pending_disk_read_bytes).c_str()
			, i->rtt);
		out += str;

		if (print_block)
		{
			if (i->downloading_piece_index >= piece_index_t(0))
			{
				char buf[50];
				std::snprintf(buf, sizeof(buf), "%d:%d"
					, static_cast<int>(i->downloading_piece_index), i->downloading_block_index);
				out += progress_bar(
					i->downloading_progress * 1000 / i->downloading_total, 14, col_green, '-', '#', buf);
			}
			else
			{
				out += progress_bar(0, 14);
			}
		}

		out += " ";

		if (i->flags & lt::peer_info::handshake)
		{
			out += esc("31");
			out += " waiting for handshake";
			out += esc("0");
		}
		else if (i->flags & lt::peer_info::connecting)
		{
			out += esc("31");
			out += " connecting to peer";
			out += esc("0");
		}
		else
		{
			out += " ";
			out += i->client;
		}
		out += "\x1b[K\n";
		++pos;
		if (pos >= max_lines) break;
	}
	return pos;
}

lt::storage_mode_t allocation_mode = lt::storage_mode_sparse;
std::string save_path(".");
int torrent_upload_limit = 0;
int torrent_download_limit = 0;
std::string monitor_dir;
int poll_interval = 5;
int max_connections_per_torrent = 50;
bool seed_mode = false;
bool stats_enabled = false;
bool exit_on_finish = false;

bool share_mode = false;

bool quit = false;

#ifndef _WIN32
void signal_handler(int)
{
	// make the main loop terminate
	quit = true;
}
#endif

// if non-empty, a peer that will be added to all torrents
std::string peer;

void print_settings(int const start, int const num
	, char const* const type)
{
	for (int i = start; i < start + num; ++i)
	{
		char const* name = lt::name_for_setting(i);
		if (!name || name[0] == '\0') continue;
		std::printf("%s=<%s>\n", name, type);
	}
}

void assign_setting(lt::settings_pack& settings, std::string const& key, char const* value)
{
	int const sett_name = lt::setting_by_name(key);
	if (sett_name < 0)
	{
		std::fprintf(stderr, "unknown setting: \"%s\"\n", key.c_str());
		std::exit(1);
	}

	using lt::settings_pack;

	switch (sett_name & settings_pack::type_mask)
	{
		case settings_pack::string_type_base:
			settings.set_str(sett_name, value);
			break;
		case settings_pack::bool_type_base:
			if (value == "1"_sv || value == "on"_sv || value == "true"_sv)
			{
				settings.set_bool(sett_name, true);
			}
			else if (value == "0"_sv || value == "off"_sv || value == "false"_sv)
			{
				settings.set_bool(sett_name, false);
			}
			else
			{
				std::fprintf(stderr, "invalid value for \"%s\". expected 0 or 1\n"
					, key.c_str());
				std::exit(1);
			}
			break;
		case settings_pack::int_type_base:
			using namespace lt::literals;
			static std::map<lt::string_view, int> const enums = {
				{"no_piece_suggestions"_sv, settings_pack::no_piece_suggestions},
				{"suggest_read_cache"_sv, settings_pack::suggest_read_cache},
				{"fixed_slots_choker"_sv, settings_pack::fixed_slots_choker},
				{"rate_based_choker"_sv, settings_pack::rate_based_choker},
				{"round_robin"_sv, settings_pack::round_robin},
				{"fastest_upload"_sv, settings_pack::fastest_upload},
				{"anti_leech"_sv, settings_pack::anti_leech},
				{"enable_os_cache"_sv, settings_pack::enable_os_cache},
				{"disable_os_cache"_sv, settings_pack::disable_os_cache},
				{"prefer_tcp"_sv, settings_pack::prefer_tcp},
				{"peer_proportional"_sv, settings_pack::peer_proportional},
				{"pe_forced"_sv, settings_pack::pe_forced},
				{"pe_enabled"_sv, settings_pack::pe_enabled},
				{"pe_disabled"_sv, settings_pack::pe_disabled},
				{"pe_plaintext"_sv, settings_pack::pe_plaintext},
				{"pe_rc4"_sv, settings_pack::pe_rc4},
				{"pe_both"_sv, settings_pack::pe_both},
				{"none"_sv, settings_pack::none},
				{"socks4"_sv, settings_pack::socks4},
				{"socks5"_sv, settings_pack::socks5},
				{"socks5_pw"_sv, settings_pack::socks5_pw},
				{"http"_sv, settings_pack::http},
				{"http_pw"_sv, settings_pack::http_pw},
				{"i2p_proxy"_sv, settings_pack::i2p_proxy},
			};

			{
				auto const it = enums.find(lt::string_view(value));
				if (it != enums.end())
				{
					settings.set_int(sett_name, it->second);
					break;
				}
			}

			static std::map<lt::string_view, lt::alert_category_t> const alert_categories = {
				{"error"_sv, lt::alert_category::error},
				{"peer"_sv, lt::alert_category::peer},
				{"port_mapping"_sv, lt::alert_category::port_mapping},
				{"storage"_sv, lt::alert_category::storage},
				{"tracker"_sv, lt::alert_category::tracker},
				{"connect"_sv, lt::alert_category::connect},
				{"status"_sv, lt::alert_category::status},
				{"ip_block"_sv, lt::alert_category::ip_block},
				{"performance_warning"_sv, lt::alert_category::performance_warning},
				{"dht"_sv, lt::alert_category::dht},
				{"session_log"_sv, lt::alert_category::session_log},
				{"torrent_log"_sv, lt::alert_category::torrent_log},
				{"peer_log"_sv, lt::alert_category::peer_log},
				{"incoming_request"_sv, lt::alert_category::incoming_request},
				{"dht_log"_sv, lt::alert_category::dht_log},
				{"dht_operation"_sv, lt::alert_category::dht_operation},
				{"port_mapping_log"_sv, lt::alert_category::port_mapping_log},
				{"picker_log"_sv, lt::alert_category::picker_log},
				{"file_progress"_sv, lt::alert_category::file_progress},
				{"piece_progress"_sv, lt::alert_category::piece_progress},
				{"upload"_sv, lt::alert_category::upload},
				{"block_progress"_sv, lt::alert_category::block_progress},
				{"all"_sv, lt::alert_category::all},
			};

			std::stringstream flags(value);
			std::string f;
			lt::alert_category_t val;
			while (std::getline(flags, f, ',')) try
			{
				auto const it = alert_categories.find(f);
				if (it == alert_categories.end())
					val |= lt::alert_category_t{unsigned(std::stoi(f))};
				else
					val |= it->second;
			}
			catch (std::invalid_argument const&)
			{
				std::fprintf(stderr, "invalid value for \"%s\". expected integer or enum value\n"
					, key.c_str());
				std::exit(1);
			}

			settings.set_int(sett_name, val);
			break;
	}
}

std::string resume_file(lt::info_hash_t const& info_hash)
{
	return path_append(save_path, path_append(".resume"
		, to_hex(info_hash.get_best()) + ".resume"));
}

void set_torrent_params(lt::add_torrent_params& p)
{
	p.max_connections = max_connections_per_torrent;
	p.max_uploads = -1;
	p.upload_limit = torrent_upload_limit;
	p.download_limit = torrent_download_limit;

	if (seed_mode) p.flags |= lt::torrent_flags::seed_mode;
	if (share_mode) p.flags |= lt::torrent_flags::share_mode;
	p.save_path = save_path;
	p.storage_mode = allocation_mode;
}

void add_magnet(lt::session& ses, lt::string_view uri)
{
	lt::error_code ec;
	lt::add_torrent_params p = lt::parse_magnet_uri(uri, ec);

	if (ec)
	{
		std::printf("invalid magnet link \"%s\": %s\n"
			, std::string(uri).c_str(), ec.message().c_str());
		return;
	}

	std::vector<char> resume_data;
	if (load_file(resume_file(p.info_hashes), resume_data))
	{
		p = lt::read_resume_data(resume_data, ec);
		if (ec) std::printf("  failed to load resume data: %s\n", ec.message().c_str());
	}

	set_torrent_params(p);

	std::printf("adding magnet: %s\n", std::string(uri).c_str());
	ses.async_add_torrent(std::move(p));
}

// return false on failure
bool add_torrent(lt::session& ses, std::string const torrent)
{
	using lt::add_torrent_params;
	using lt::storage_mode_t;

	static int counter = 0;

	std::printf("[%d] %s\n", counter++, torrent.c_str());

	lt::error_code ec;
	auto ti = std::make_shared<lt::torrent_info>(torrent, ec);
	if (ec)
	{
		std::printf("failed to load torrent \"%s\": %s\n"
			, torrent.c_str(), ec.message().c_str());
		return false;
	}

	add_torrent_params p;

	std::vector<char> resume_data;
	if (load_file(resume_file(ti->info_hashes()), resume_data))
	{
		p = lt::read_resume_data(resume_data, ec);
		if (ec) std::printf("  failed to load resume data: %s\n", ec.message().c_str());
	}

	set_torrent_params(p);

	p.ti = ti;
	p.flags &= ~lt::torrent_flags::duplicate_is_error;
	ses.async_add_torrent(std::move(p));
	return true;
}

std::vector<std::string> list_dir(std::string path
	, bool (*filter_fun)(lt::string_view)
	, lt::error_code& ec)
{
	std::vector<std::string> ret;
#ifdef TORRENT_WINDOWS
	if (!path.empty() && path[path.size()-1] != '\\') path += "\\*";
	else path += "*";

	WIN32_FIND_DATAA fd;
	HANDLE handle = FindFirstFileA(path.c_str(), &fd);
	if (handle == INVALID_HANDLE_VALUE)
	{
		ec.assign(GetLastError(), boost::system::system_category());
		return ret;
	}

	do
	{
		lt::string_view const p = fd.cFileName;
		if (filter_fun(p))
			ret.emplace_back(p);

	} while (FindNextFileA(handle, &fd));
	FindClose(handle);
#else

	if (!path.empty() && path[path.size()-1] == '/')
		path.resize(path.size()-1);

	DIR* handle = opendir(path.c_str());
	if (handle == nullptr)
	{
		ec.assign(errno, boost::system::system_category());
		return ret;
	}

	struct dirent* de;
	while ((de = readdir(handle)))
	{
		lt::string_view const p(de->d_name);
		if (filter_fun(p))
			ret.emplace_back(p);
	}
	closedir(handle);
#endif
	return ret;
}

void scan_dir(std::string const& dir_path, lt::session& ses)
{
	using namespace lt;

	error_code ec;
	std::vector<std::string> ents = list_dir(dir_path
		, [](lt::string_view p) { return p.size() > 8 && p.substr(p.size() - 8) == ".torrent"; }, ec);
	if (ec)
	{
		std::fprintf(stderr, "failed to list directory: (%s : %d) %s\n"
			, ec.category().name(), ec.value(), ec.message().c_str());
		return;
	}

	for (auto const& e : ents)
	{
		std::string const file = path_append(dir_path, e);

		// there's a new file in the monitor directory, load it up
		if (add_torrent(ses, file))
		{
			if (::remove(file.c_str()) < 0)
			{
				std::fprintf(stderr, "failed to remove torrent file: \"%s\"\n"
					, file.c_str());
			}
		}
	}
}

char const* timestamp()
{
	time_t t = std::time(nullptr);
	tm* timeinfo = std::localtime(&t);
	static char str[200];
	std::strftime(str, 200, "%b %d %X", timeinfo);
	return str;
}

void print_alert(lt::alert const* a, std::string& str)
{
	using namespace lt;

	if (a->category() & alert_category::error)
	{
		str += esc("31");
	}
	else if (a->category() & (alert_category::peer | alert_category::storage))
	{
		str += esc("33");
	}
	str += "[";
	str += timestamp();
	str += "] ";
	str += a->message();
	str += esc("0");

	static auto const first_ts = a->timestamp();

	if (g_log_file)
		std::fprintf(g_log_file, "[%" PRId64 "] %s\n"
			, std::int64_t(duration_cast<std::chrono::milliseconds>(a->timestamp() - first_ts).count())
			,  a->message().c_str());
}

int save_file(std::string const& filename, std::vector<char> const& v)
{
	std::fstream f(filename, std::ios_base::trunc | std::ios_base::out | std::ios_base::binary);
	f.write(v.data(), int(v.size()));
	return !f.fail();
}

// returns true if the alert was handled (and should not be printed to the log)
// returns false if the alert was not handled
bool handle_alert(torrent_view& view, session_view& ses_view
	, lt::session&, lt::alert* a)
{
	using namespace lt;

	if (session_stats_alert* s = alert_cast<session_stats_alert>(a))
	{
		ses_view.update_counters(s->counters(), s->timestamp());
		return !stats_enabled;
	}

#ifndef TORRENT_DISABLE_DHT
	if (dht_stats_alert* p = alert_cast<dht_stats_alert>(a))
	{
		dht_active_requests = p->active_requests;
		dht_routing_table = p->routing_table;
		return true;
	}
#endif

#ifdef TORRENT_SSL_PEERS
	if (torrent_need_cert_alert* p = alert_cast<torrent_need_cert_alert>(a))
	{
		torrent_handle h = p->handle;
		std::string base_name = path_append("certificates", to_hex(h.info_hash()));
		std::string cert = base_name + ".pem";
		std::string priv = base_name + "_key.pem";

#ifdef TORRENT_WINDOWS
		struct ::_stat st;
		int ret = ::_stat(cert.c_str(), &st);
		if (ret < 0 || (st.st_mode & _S_IFREG) == 0)
#else
		struct ::stat st;
		int ret = ::stat(cert.c_str(), &st);
		if (ret < 0 || (st.st_mode & S_IFREG) == 0)
#endif
		{
			char msg[256];
			std::snprintf(msg, sizeof(msg), "ERROR. could not load certificate %s: %s\n"
				, cert.c_str(), std::strerror(errno));
			if (g_log_file) std::fprintf(g_log_file, "[%s] %s\n", timestamp(), msg);
			return true;
		}

#ifdef TORRENT_WINDOWS
		ret = ::_stat(priv.c_str(), &st);
		if (ret < 0 || (st.st_mode & _S_IFREG) == 0)
#else
		ret = ::stat(priv.c_str(), &st);
		if (ret < 0 || (st.st_mode & S_IFREG) == 0)
#endif
		{
			char msg[256];
			std::snprintf(msg, sizeof(msg), "ERROR. could not load private key %s: %s\n"
				, priv.c_str(), std::strerror(errno));
			if (g_log_file) std::fprintf(g_log_file, "[%s] %s\n", timestamp(), msg);
			return true;
		}

		char msg[256];
		std::snprintf(msg, sizeof(msg), "loaded certificate %s and key %s\n", cert.c_str(), priv.c_str());
		if (g_log_file) std::fprintf(g_log_file, "[%s] %s\n", timestamp(), msg);

		h.set_ssl_certificate(cert, priv, "certificates/dhparams.pem", "1234");
		h.resume();
	}
#endif

	// don't log every peer we try to connect to
	if (alert_cast<peer_connect_alert>(a)) return true;

	if (peer_disconnected_alert* pd = alert_cast<peer_disconnected_alert>(a))
	{
		// ignore failures to connect and peers not responding with a
		// handshake. The peers that we successfully connect to and then
		// disconnect is more interesting.
		if (pd->op == operation_t::connect
			|| pd->error == errors::timed_out_no_handshake)
			return true;
	}

#ifdef _MSC_VER
// it seems msvc makes the definitions of 'p' escape the if-statement here
#pragma warning(push)
#pragma warning(disable: 4456)
#endif

	if (metadata_received_alert* p = alert_cast<metadata_received_alert>(a))
	{
		torrent_handle h = p->handle;
		h.save_resume_data(torrent_handle::save_info_dict);
		++num_outstanding_resume_data;
	}

	if (add_torrent_alert* p = alert_cast<add_torrent_alert>(a))
	{
		if (p->error)
		{
			std::fprintf(stderr, "failed to add torrent: %s %s\n"
				, p->params.ti ? p->params.ti->name().c_str() : p->params.name.c_str()
				, p->error.message().c_str());
		}
		else
		{
			torrent_handle h = p->handle;

			h.save_resume_data(torrent_handle::save_info_dict | torrent_handle::only_if_modified);
			++num_outstanding_resume_data;

			// if we have a peer specified, connect to it
			if (!peer.empty())
			{
				auto port = peer.find_last_of(':');
				if (port != std::string::npos)
				{
					peer[port++] = '\0';
					char const* ip = peer.data();
					int const peer_port = atoi(peer.data() + port);
					error_code ec;
					if (peer_port > 0)
						h.connect_peer(tcp::endpoint(make_address(ip, ec), std::uint16_t(peer_port)));
				}
			}
		}
	}

	if (torrent_finished_alert* p = alert_cast<torrent_finished_alert>(a))
	{
		p->handle.set_max_connections(max_connections_per_torrent / 2);

		// write resume data for the finished torrent
		// the alert handler for save_resume_data_alert
		// will save it to disk
		torrent_handle h = p->handle;
		h.save_resume_data(torrent_handle::save_info_dict);
		++num_outstanding_resume_data;
		if (exit_on_finish) quit = true;
	}

	if (save_resume_data_alert* p = alert_cast<save_resume_data_alert>(a))
	{
		--num_outstanding_resume_data;
		auto const buf = write_resume_data_buf(p->params);
		save_file(resume_file(p->params.info_hashes), buf);
	}

	if (save_resume_data_failed_alert* p = alert_cast<save_resume_data_failed_alert>(a))
	{
		--num_outstanding_resume_data;
		// don't print the error if it was just that we didn't need to save resume
		// data. Returning true means "handled" and not printed to the log
		return p->error == lt::errors::resume_data_not_modified;
	}

	if (torrent_paused_alert* p = alert_cast<torrent_paused_alert>(a))
	{
		// write resume data for the finished torrent
		// the alert handler for save_resume_data_alert
		// will save it to disk
		torrent_handle h = p->handle;
		h.save_resume_data(torrent_handle::save_info_dict);
		++num_outstanding_resume_data;
	}

	if (state_update_alert* p = alert_cast<state_update_alert>(a))
	{
		view.update_torrents(std::move(p->status));
		return true;
	}

	if (torrent_removed_alert* p = alert_cast<torrent_removed_alert>(a))
	{
		view.remove_torrent(std::move(p->handle));
	}
	return false;

#ifdef _MSC_VER
#pragma warning(pop)
#endif

}

void pop_alerts(torrent_view& view, session_view& ses_view
	, lt::session& ses, std::deque<std::string>& events)
{
	std::vector<lt::alert*> alerts;
	ses.pop_alerts(&alerts);
	for (auto a : alerts)
	{
		if (::handle_alert(view, ses_view, ses, a)) continue;

		// if we didn't handle the alert, print it to the log
		std::string event_string;
		print_alert(a, event_string);
		events.push_back(event_string);
		if (events.size() >= 20) events.pop_front();
	}
}

void print_piece(lt::partial_piece_info const& pp
	, std::vector<lt::peer_info> const& peers
	, std::string& out)
{
	using namespace lt;

	char str[1024];
	int const piece = static_cast<int>(pp.piece_index);
	int const num_blocks = pp.blocks_in_piece;

	std::snprintf(str, sizeof(str), "%5d:[", piece);
	out += str;
	string_view last_color;
	for (int j = 0; j < num_blocks; ++j)
	{
		int const index = peer_index(pp.blocks[j].peer(), peers) % 36;
		bool const snubbed = index >= 0 ? bool(peers[std::size_t(index)].flags & lt::peer_info::snubbed) : false;
		char const* chr = " ";
		char const* color = "";

		if (pp.blocks[j].bytes_progress > 0
				&& pp.blocks[j].state == block_info::requested)
		{
			if (pp.blocks[j].num_peers > 1) color = esc("0;1");
			else color = snubbed ? esc("0;35") : esc("0;33");

#ifndef TORRENT_WINDOWS
			static char const* const progress[] = {
				"\u2581", "\u2582", "\u2583", "\u2584",
				"\u2585", "\u2586", "\u2587", "\u2588"
			};
			chr = progress[pp.blocks[j].bytes_progress * 8 / pp.blocks[j].block_size];
#else
			static char const* const progress[] = { "\xb0", "\xb1", "\xb2" };
			chr = progress[pp.blocks[j].bytes_progress * 3 / pp.blocks[j].block_size];
#endif
		}
		else if (pp.blocks[j].state == block_info::finished) color = esc("32;7");
		else if (pp.blocks[j].state == block_info::writing) color = esc("36;7");
		else if (pp.blocks[j].state == block_info::requested)
		{
			color = snubbed ? esc("0;35") : esc("0");
			chr = "=";
		}
		else { color = esc("0"); chr = " "; }

		if (last_color != color)
		{
			out += color;
			last_color = color;
		}
		out += chr;
	}
	out += esc("0");
	out += "]";
}

bool is_resume_file(std::string const& s)
{
	static std::string const hex_digit = "0123456789abcdef";
	if (s.size() != 40 + 7) return false;
	if (s.substr(40) != ".resume") return false;
	for (char const c : s.substr(0, 40))
	{
		if (hex_digit.find(c) == std::string::npos) return false;
	}
	return true;
}

void print_usage()
{
	std::fprintf(stderr, R"(usage: client_test [OPTIONS] [TORRENT|MAGNETURL]
OPTIONS:

CLIENT OPTIONS
  -h                    print this message
  -f <log file>         logs all events to the given file
  -s <path>             sets the save path for downloads. This also determines
                        the resume data save directory. Torrents from the resume
                        directory are automatically added to the session on
                        startup.
  -m <path>             sets the .torrent monitor directory. torrent files
                        dropped in the directory are added the session and the
                        resume data directory, and removed from the monitor dir.
  -t <seconds>          sets the scan interval of the monitor dir
  -F <milliseconds>     sets the UI refresh rate. This is the number of
                        milliseconds between screen refreshes.
  -k                    enable high performance settings. This overwrites any other
                        previous command line options, so be sure to specify this first
  -G                    Add torrents in seed-mode (i.e. assume all pieces
                        are present and check hashes on-demand)
  -e <loops>            exit client after the specified number of iterations
                        through the main loop
  -O                    print session stats counters to the log
  -1                    exit on first torrent completing (useful for benchmarks))"
#ifdef TORRENT_UTP_LOG_ENABLE
R"(
  -q                    Enable uTP transport-level verbose logging
)"
#endif
R"(
LIBTORRENT SETTINGS
  --<name-of-setting>=<value>
                        set the libtorrent setting <name> to <value>
  --list-settings       print all libtorrent settings and exit

BITTORRENT OPTIONS
  -T <limit>            sets the max number of connections per torrent
  -U <rate>             sets per-torrent upload rate
  -D <rate>             sets per-torrent download rate
  -Q                    enables share mode. Share mode attempts to maximize
                        share ratio rather than downloading
  -r <IP:port>          connect to specified peer

NETWORK OPTIONS
  -x <file>             loads an emule IP-filter file
  -Y                    Rate limit local peers)"
#if TORRENT_USE_I2P
R"(  -i <i2p-host>         the hostname to an I2P SAM bridge to use
)"
#endif
R"(
DISK OPTIONS
  -a <mode>             sets the allocation mode. [sparse|allocate]
  -0                    disable disk I/O, read garbage and don't flush to disk

TORRENT is a path to a .torrent file
MAGNETURL is a magnet link

alert mask flags:
	error peer port_mapping storage tracker connect status ip_block
	performance_warning dht session_log torrent_log peer_log incoming_request
	dht_log dht_operation port_mapping_log picker_log file_progress piece_progress
	upload block_progress all

examples:
  --alert_mask=error,port_mapping,tracker,connect,session_log
  --alert_mask=error,session_log,torrent_log,peer_log
  --alert_mask=error,dht,dht_log,dht_operation
  --alert_mask=all
)") ;
}

} // anonymous namespace

int main(int argc, char* argv[])
{
#ifndef _WIN32
	// sets the terminal to single-character mode
	// and resets when destructed
	set_keypress s_;
#endif

	if (argc == 1)
	{
		print_usage();
		return 0;
	}

	using lt::settings_pack;
	using lt::session_handle;

	torrent_view view;
	session_view ses_view;

	lt::session_params params;

#ifndef TORRENT_DISABLE_DHT

	std::vector<char> in;
	if (load_file(".ses_state", in))
		params = read_session_params(in, session_handle::save_dht_state);

	params.settings.set_bool(settings_pack::dht_privacy_lookups, true);
#endif

	auto& settings = params.settings;

	settings.set_str(settings_pack::user_agent, "client_test/" LIBTORRENT_VERSION);
	settings.set_int(settings_pack::alert_mask
		, lt::alert_category::error
		| lt::alert_category::peer
		| lt::alert_category::port_mapping
		| lt::alert_category::storage
		| lt::alert_category::tracker
		| lt::alert_category::connect
		| lt::alert_category::status
		| lt::alert_category::ip_block
		| lt::alert_category::performance_warning
		| lt::alert_category::dht
		| lt::alert_category::incoming_request
		| lt::alert_category::dht_operation
		| lt::alert_category::port_mapping_log
		| lt::alert_category::file_progress);

	lt::time_duration refresh_delay = lt::milliseconds(500);
	bool rate_limit_locals = false;

	std::deque<std::string> events;
	int loop_limit = -1;

	lt::time_point next_dir_scan = lt::clock_type::now();

	// load the torrents given on the commandline
	std::vector<lt::string_view> torrents;
	lt::ip_filter loaded_ip_filter;

	for (int i = 1; i < argc; ++i)
	{
		if (argv[i][0] != '-')
		{
			torrents.push_back(argv[i]);
			continue;
		}

		if (argv[i] == "--list-settings"_sv)
		{
			// print all libtorrent settings and exit
			print_settings(settings_pack::string_type_base
				, settings_pack::num_string_settings, "string");
			print_settings(settings_pack::bool_type_base
				, settings_pack::num_bool_settings, "bool");
			print_settings(settings_pack::int_type_base
				, settings_pack::num_int_settings, "int");
			return 0;
		}

		// maybe this is an assignment of a libtorrent setting
		if (argv[i][1] == '-' && strchr(argv[i], '=') != nullptr)
		{
			char const* equal = strchr(argv[i], '=');
			char const* start = argv[i]+2;
			// +2 is to skip the --
			std::string const key(start, std::size_t(equal - start));
			char const* value = equal + 1;

			assign_setting(settings, key, value);
			continue;
		}

		// command line switches that don't take an argument
		switch (argv[i][1])
		{
			case 'k': settings = lt::high_performance_seed(); continue;
			case 'G': seed_mode = true; continue;
			case 'O': stats_enabled = true; continue;
			case '1': exit_on_finish = true; continue;
#ifdef TORRENT_UTP_LOG_ENABLE
			case 'q':
				lt::set_utp_stream_logging(true);
				continue;
#endif
			case 'Q': share_mode = true; continue;
			case 'Y': rate_limit_locals = true; continue;
			case '0': params.disk_io_constructor = lt::disabled_disk_io_constructor; continue;
			case 'h': print_usage(); return 0;
		}

		// if there's a flag but no argument following, ignore it
		if (argc == i + 1)
		{
			std::fprintf(stderr, "invalid command line argument or missing parameter: %s\n", argv[i]);
			return 1;
		}
		char const* arg = argv[i+1];
		if (arg == nullptr) arg = "";

		switch (argv[i][1])
		{
			case 'f': g_log_file = std::fopen(arg, "w+"); break;
			case 's': save_path = make_absolute_path(arg); break;
			case 'U': torrent_upload_limit = atoi(arg) * 1000; break;
			case 'D': torrent_download_limit = atoi(arg) * 1000; break;
			case 'm': monitor_dir = make_absolute_path(arg); break;
			case 't': poll_interval = atoi(arg); break;
			case 'F': refresh_delay = lt::milliseconds(atoi(arg)); break;
			case 'a': allocation_mode = (arg == std::string("sparse"))
				? lt::storage_mode_sparse
				: lt::storage_mode_allocate;
				break;
			case 'x':
				{
					std::fstream filter(arg, std::ios_base::in);
					if (!filter.fail())
					{
						std::regex regex(R"(^\s*([0-9\.]+)\s*-\s*([0-9\.]+)\s+([0-9]+)$)");

						std::string line;
						while (std::getline(filter, line))
						{
							std::smatch m;
							if (std::regex_match(line, m, regex))
							{
								address_v4 start = make_address_v4(m[1]);
								address_v4 last = make_address_v4(m[2]);
								loaded_ip_filter.add_rule(start, last, stoi(m[3]) <= 127 ? lt::ip_filter::blocked : 0);
							}
						}
					}
				}
				break;
			case 'T': max_connections_per_torrent = atoi(arg); break;
			case 'r': peer = arg; break;
			case 'e':
				{
					loop_limit = atoi(arg);
					break;
				}
		}
		++i; // skip the argument
	}

	// create directory for resume files
#ifdef TORRENT_WINDOWS
	int mkdir_ret = _mkdir(path_append(save_path, ".resume").c_str());
#else
	int mkdir_ret = mkdir(path_append(save_path, ".resume").c_str(), 0777);
#endif
	if (mkdir_ret < 0 && errno != EEXIST)
	{
		std::fprintf(stderr, "failed to create resume file directory: (%d) %s\n"
			, errno, strerror(errno));
	}

	lt::session ses(std::move(params));

	if (rate_limit_locals)
	{
		lt::ip_filter pcf;
		pcf.add_rule(make_address_v4("0.0.0.0")
			, make_address_v4("255.255.255.255")
			, 1 << static_cast<std::uint32_t>(lt::session::global_peer_class_id));
		pcf.add_rule(make_address_v6("::")
			, make_address_v6("ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"), 1);
		ses.set_peer_class_filter(pcf);
	}

	ses.set_ip_filter(loaded_ip_filter);

	for (auto const& i : torrents)
	{
		if (i.substr(0, 7) == "magnet:") add_magnet(ses, i);
		else add_torrent(ses, std::string(i));
	}

	std::thread resume_data_loader([&ses]
	{
		// load resume files
		lt::error_code ec;
		std::string const resume_dir = path_append(save_path, ".resume");
		std::vector<std::string> ents = list_dir(resume_dir
			, [](lt::string_view p) { return p.size() > 7 && p.substr(p.size() - 7) == ".resume"; }, ec);
		if (ec)
		{
		std::fprintf(stderr, "failed to list resume directory \"%s\": (%s : %d) %s\n"
			, resume_dir.c_str(), ec.category().name(), ec.value(), ec.message().c_str());
		}
		else
		{
			for (auto const& e : ents)
			{
				// only load resume files of the form <info-hash>.resume
				if (!is_resume_file(e)) continue;
				std::string const file = path_append(resume_dir, e);

				std::vector<char> resume_data;
				if (!load_file(file, resume_data))
				{
					std::printf("  failed to load resume file \"%s\": %s\n"
						, file.c_str(), ec.message().c_str());
					continue;
				}
				add_torrent_params p = lt::read_resume_data(resume_data, ec);
				if (ec)
				{
					std::printf("  failed to parse resume data \"%s\": %s\n"
						, file.c_str(), ec.message().c_str());
					continue;
				}

				ses.async_add_torrent(std::move(p));
			}
		}
	});

	// main loop
	std::vector<lt::peer_info> peers;

#ifndef _WIN32
	signal(SIGTERM, signal_handler);
	signal(SIGINT, signal_handler);
#endif

	while (!quit && loop_limit != 0)
	{
		if (loop_limit > 0) --loop_limit;

		ses.post_torrent_updates();
		ses.post_session_stats();
		ses.post_dht_stats();

		auto const [terminal_width, terminal_height] = terminal_size();

		// the ratio of torrent-list and details below depend on the number of
		// torrents we have in the session
		int const height = std::min(terminal_height / 2
			, std::max(5, view.num_visible_torrents() + 2));
		view.set_size(terminal_width, height);
		ses_view.set_pos(height);
		ses_view.set_width(terminal_width);

		int c = 0;
		if (sleep_and_input(&c, refresh_delay))
		{

#ifdef _WIN32
			constexpr int escape_seq = 224;
			constexpr int left_arrow = 75;
			constexpr int right_arrow = 77;
			constexpr int up_arrow = 72;
			constexpr int down_arrow = 80;
#else
			constexpr int escape_seq = 27;
			constexpr int left_arrow = 68;
			constexpr int right_arrow = 67;
			constexpr int up_arrow = 65;
			constexpr int down_arrow = 66;
#endif

			torrent_handle h = view.get_active_handle();

			if (c == EOF)
			{
				quit = true;
				break;
			}
			do
			{
				if (c == escape_seq)
				{
					// escape code, read another character
#ifdef _WIN32
					int c2 = _getch();
#else
					int c2 = getc(stdin);
					if (c2 == EOF)
					{
						quit = true;
						break;
					}
					if (c2 != '[') continue;
					c2 = getc(stdin);
#endif
					if (c2 == EOF)
					{
						quit = true;
						break;
					}
					if (c2 == left_arrow)
					{
						int const filter = view.filter();
						if (filter > 0)
						{
							view.set_filter(filter - 1);
							h = view.get_active_handle();
						}
					}
					else if (c2 == right_arrow)
					{
						int const filter = view.filter();
						if (filter < torrent_view::torrents_max - 1)
						{
							view.set_filter(filter + 1);
							h = view.get_active_handle();
						}
					}
					else if (c2 == up_arrow)
					{
						view.arrow_up();
						h = view.get_active_handle();
					}
					else if (c2 == down_arrow)
					{
						view.arrow_down();
						h = view.get_active_handle();
					}
				}

				if (c == ' ')
				{
					if (ses.is_paused()) ses.resume();
					else ses.pause();
				}

				if (c == '[' && h.is_valid())
				{
					h.queue_position_up();
				}

				if (c == ']' && h.is_valid())
				{
					h.queue_position_down();
				}

				// add magnet link
				if (c == 'm')
				{
					char url[4096];
					url[0] = '\0';
					puts("Enter magnet link:\n");

#ifndef _WIN32
					// enable terminal echo temporarily
					set_keypress echo_(set_keypress::echo | set_keypress::canonical);
#endif
					if (std::scanf("%4095s", url) == 1) add_magnet(ses, url);
					else std::printf("failed to read magnet link\n");
				}

				if (c == 'q')
				{
					quit = true;
					break;
				}

				if (c == 'W' && h.is_valid())
				{
					std::set<std::string> seeds = h.url_seeds();
					for (auto const& s : seeds)
						h.remove_url_seed(s);
				}

				if (c == 'D' && h.is_valid())
				{
					torrent_status const& st = view.get_active_torrent();
					std::printf("\n\nARE YOU SURE YOU WANT TO DELETE THE FILES FOR '%s'. THIS OPERATION CANNOT BE UNDONE. (y/N)"
						, st.name.c_str());
#ifndef _WIN32
					// enable terminal echo temporarily
					set_keypress echo_(set_keypress::echo | set_keypress::canonical);
#endif
					char response = 'n';
					int scan_ret = std::scanf("%c", &response);
					if (scan_ret == 1 && response == 'y')
					{
						// also delete the resume file
						std::string const rpath = resume_file(st.info_hashes);
						if (::remove(rpath.c_str()) < 0)
							std::printf("failed to delete resume file (\"%s\")\n"
								, rpath.c_str());

						if (st.handle.is_valid())
						{
							ses.remove_torrent(st.handle, lt::session::delete_files);
						}
						else
						{
							std::printf("failed to delete torrent, invalid handle: %s\n"
								, st.name.c_str());
						}
					}
				}

				if (c == 'j' && h.is_valid())
				{
					h.force_recheck();
				}

				if (c == 'r' && h.is_valid())
				{
					h.force_reannounce();
				}

				if (c == 's' && h.is_valid())
				{
					torrent_status const& ts = view.get_active_torrent();
					h.set_flags(~ts.flags, lt::torrent_flags::sequential_download);
				}

				if (c == 'R')
				{
					// save resume data for all torrents
					std::vector<torrent_status> const torr = ses.get_torrent_status(
						[](torrent_status const& st)
						{ return st.need_save_resume; }, {});
					for (torrent_status const& st : torr)
					{
						st.handle.save_resume_data(torrent_handle::save_info_dict);
						++num_outstanding_resume_data;
					}
				}

				if (c == 'o' && h.is_valid())
				{
					torrent_status const& ts = view.get_active_torrent();
					int num_pieces = ts.num_pieces;
					if (num_pieces > 300) num_pieces = 300;
					for (piece_index_t i(0); i < piece_index_t(num_pieces); ++i)
					{
						h.set_piece_deadline(i, (static_cast<int>(i)+5) * 1000
							, torrent_handle::alert_when_available);
					}
				}

				if (c == 'v' && h.is_valid())
				{
					h.scrape_tracker();
				}

				if (c == 'p' && h.is_valid())
				{
					torrent_status const& ts = view.get_active_torrent();
					if ((ts.flags & (lt::torrent_flags::auto_managed
						| lt::torrent_flags::paused)) == lt::torrent_flags::paused)
					{
						h.set_flags(lt::torrent_flags::auto_managed);
					}
					else
					{
						h.unset_flags(lt::torrent_flags::auto_managed);
						h.pause(torrent_handle::graceful_pause);
					}
				}

				// toggle force-start
				if (c == 'k' && h.is_valid())
				{
					torrent_status const& ts = view.get_active_torrent();
					h.set_flags(
						~(ts.flags & lt::torrent_flags::auto_managed),
						lt::torrent_flags::auto_managed);
					if ((ts.flags & lt::torrent_flags::auto_managed)
						&& (ts.flags & lt::torrent_flags::paused))
					{
						h.resume();
					}
				}

				if (c == 'c' && h.is_valid())
				{
					h.clear_error();
				}

				// toggle displays
				if (c == 't') print_trackers = !print_trackers;
				if (c == 'i') print_peers = !print_peers;
				if (c == 'l') print_log = !print_log;
				if (c == 'd') print_downloads = !print_downloads;
				if (c == 'y') print_matrix = !print_matrix;
				if (c == 'f') print_file_progress = !print_file_progress;
				if (c == 'P') show_pad_files = !show_pad_files;
				if (c == 'g') show_dht_status = !show_dht_status;
				if (c == 'x') print_disk_stats = !print_disk_stats;
				// toggle columns
				if (c == '1') print_ip = !print_ip;
				if (c == '2') print_connecting_peers = !print_connecting_peers;
				if (c == '3') print_timers = !print_timers;
				if (c == '4') print_block = !print_block;
				if (c == '6') print_fails = !print_fails;
				if (c == '7') print_send_bufs = !print_send_bufs;
				if (c == '8') print_local_ip = !print_local_ip;
				if (c == 'h')
				{
					clear_screen();
					set_cursor_pos(0,0);
					print(
R"(HELP SCREEN (press any key to dismiss)

CLIENT OPTIONS

[q] quit client                                 [m] add magnet link

TORRENT ACTIONS
[p] pause/resume selected torrent               [W] remove all web seeds
[s] toggle sequential download                  [j] force recheck
[space] toggle session pause                    [c] clear error
[v] scrape                                      [D] delete torrent and data
[r] force reannounce                            [R] save resume data for all torrents
[o] set piece deadlines (sequential dl)         [P] toggle auto-managed
[k] toggle force-started                        [W] remove all web seeds
 [  move queue position closer to beginning
 ]  move queue position closer to end

DISPLAY OPTIONS
left/right arrow keys: select torrent filter
up/down arrow keys: select torrent
[i] toggle show peers                           [d] toggle show downloading pieces
[P] show pad files (in file list)               [f] toggle show files
[g] show DHT                                    [x] toggle disk cache stats
[t] show trackers                               [l] toggle show log
[y] toggle show piece matrix

COLUMN OPTIONS
[1] toggle IP column                            [2] toggle show peer connection attempts
[3] toggle timers column                        [4] toggle block progress column
                                                [6] toggle failures column
[7] toggle send buffers column                  [8] toggle local IP column
)");
					int tmp;
					while (sleep_and_input(&tmp, lt::milliseconds(500)) == false);
				}

			} while (sleep_and_input(&c, lt::milliseconds(0)));
			if (c == 'q')
			{
				quit = true;
				break;
			}
		}

		pop_alerts(view, ses_view, ses, events);

		std::string out;

		char str[500];

		int pos = view.height() + ses_view.height();
		set_cursor_pos(0, pos);

		torrent_handle h = view.get_active_handle();

#ifndef TORRENT_DISABLE_DHT
		if (show_dht_status)
		{
			// TODO: 3 expose these counters as performance counters
/*
			std::snprintf(str, sizeof(str), "DHT nodes: %d DHT cached nodes: %d "
				"total DHT size: %" PRId64 " total observers: %d\n"
				, sess_stat.dht_nodes, sess_stat.dht_node_cache, sess_stat.dht_global_nodes
				, sess_stat.dht_total_allocations);
			out += str;
*/

			int bucket = 0;
			for (lt::dht_routing_bucket const& n : dht_routing_table)
			{
				char const* progress_bar =
					"################################"
					"################################"
					"################################"
					"################################";
				char const* short_progress_bar = "--------";
				std::snprintf(str, sizeof(str)
					, "%3d [%3d, %d] %s%s\x1b[K\n"
					, bucket, n.num_nodes, n.num_replacements
					, progress_bar + (128 - n.num_nodes)
					, short_progress_bar + (8 - std::min(8, n.num_replacements)));
				out += str;
				pos += 1;
				++bucket;
			}

			for (lt::dht_lookup const& l : dht_active_requests)
			{
				std::snprintf(str, sizeof(str)
					, "  %10s target: %s "
					"[limit: %2d] "
					"in-flight: %-2d "
					"left: %-3d "
					"1st-timeout: %-2d "
					"timeouts: %-2d "
					"responses: %-2d "
					"last_sent: %-2d "
					"\x1b[K\n"
					, l.type
					, to_hex(l.target).c_str()
					, l.branch_factor
					, l.outstanding_requests
					, l.nodes_left
					, l.first_timeout
					, l.timeouts
					, l.responses
					, l.last_sent);
				out += str;
				pos += 1;
			}
		}
#endif
		lt::time_point const now = lt::clock_type::now();
		if (h.is_valid())
		{
			torrent_status const& s = view.get_active_torrent();

			print((piece_bar(s.pieces, terminal_width - 2) + "\x1b[K\n").c_str());
			pos += 1;

			if ((print_downloads && s.state != torrent_status::seeding)
				|| print_peers)
				h.get_peer_info(peers);

			if (print_peers && !peers.empty())
			{
				using lt::peer_info;
				// sort connecting towards the bottom of the list, and by peer_id
				// otherwise, to keep the list as stable as possible
				std::sort(peers.begin(), peers.end()
					, [](peer_info const& lhs, peer_info const& rhs)
					{
						{
							bool const l = bool(lhs.flags & peer_info::connecting);
							bool const r = bool(rhs.flags & peer_info::connecting);
							if (l != r) return l < r;
						}

						{
							bool const l = bool(lhs.flags & peer_info::handshake);
							bool const r = bool(rhs.flags & peer_info::handshake);
							if (l != r) return l < r;
						}

						return lhs.pid < rhs.pid;
					});
				pos += print_peer_info(out, peers, terminal_height - pos - 2);
			}

			if (print_trackers)
			{
				snprintf(str, sizeof(str), "next_announce: %4" PRId64 " | current tracker: %s\x1b[K\n"
					, std::int64_t(duration_cast<seconds>(s.next_announce).count())
					, s.current_tracker.c_str());
				out += str;
				pos += 1;
				std::vector<lt::announce_entry> tr = h.trackers();
				for (lt::announce_entry const& ae : h.trackers())
				{
					std::snprintf(str, sizeof(str), "%2d %-55s %s\x1b[K\n"
						, ae.tier, ae.url.c_str(), ae.verified?"OK ":"-  ");
					out += str;
					pos += 1;
					int idx = 0;
					for (auto const& ep : ae.endpoints)
					{
						++idx;
						if (pos + 1 >= terminal_height) break;
						if (!ep.enabled) continue;
						for (lt::protocol_version const v : {lt::protocol_version::V1, lt::protocol_version::V2})
						{
							if (!s.info_hashes.has(v)) continue;
							auto const& av = ep.info_hashes[v];

							std::snprintf(str, sizeof(str), "  [%2d] fails: %-3d (%-3d) %s %5d \"%s\" %s\x1b[K\n"
								, idx
								, av.fails, ae.fail_limit
								, to_string(int(total_seconds(av.next_announce - now)), 8).c_str()
								, av.min_announce > now ? int(total_seconds(av.min_announce - now)) : 0
								, av.last_error ? av.last_error.message().c_str() : ""
								, av.message.c_str());
							out += str;
							pos += 1;
							// we only need to show this error once, not for every
							// endpoint
							if (av.last_error == boost::asio::error::host_not_found)
								goto done;
						}
					}
done:

					if (pos + 1 >= terminal_height) break;
				}
			}

			if (print_matrix)
			{
				int height_out = 0;
				print(piece_matrix(s.pieces, terminal_width, &height_out).c_str());
				pos += height_out;
			}

			if (print_downloads)
			{
				std::vector<lt::partial_piece_info> queue = h.get_download_queue();

				int p = 0; // this is horizontal position
				for (lt::partial_piece_info const& i : queue)
				{
					if (pos + 3 >= terminal_height) break;

					print_piece(i, peers, out);

					int const num_blocks = i.blocks_in_piece;
					p += num_blocks + 8;
					bool continuous_mode = 8 + num_blocks > terminal_width;
					if (continuous_mode)
					{
						while (p > terminal_width)
						{
							p -= terminal_width;
							++pos;
						}
					}
					else if (p + num_blocks + 8 > terminal_width)
					{
						out += "\x1b[K\n";
						pos += 1;
						p = 0;
					}
				}
				if (p != 0)
				{
					out += "\x1b[K\n";
					pos += 1;
				}

				std::snprintf(str, sizeof(str), "%s %s downloading | %s %s writing | %s %s flushed | %s %s snubbed | = requested\x1b[K\n"
					, esc("33;7"), esc("0") // downloading
					, esc("36;7"), esc("0") // writing
					, esc("32;7"), esc("0") // flushed
					, esc("35;7"), esc("0") // snubbed
					);
				out += str;
				pos += 1;
			}

			if (print_file_progress && s.has_metadata)
			{
				std::vector<std::int64_t> const file_progress = h.file_progress();
				std::vector<lt::open_file_state> file_status = h.file_status();
				std::vector<lt::download_priority_t> file_prio = h.get_file_priorities();
				auto f = file_status.begin();
				std::shared_ptr<const lt::torrent_info> ti = h.torrent_file();

				int p = 0; // this is horizontal position
				for (file_index_t i(0); i < file_index_t(ti->num_files()); ++i)
				{
					auto const idx = std::size_t(static_cast<int>(i));
					if (pos + 1 >= terminal_height) break;

					bool const pad_file = ti->files().pad_file_at(i);
					if (pad_file && !show_pad_files) continue;

					int const progress = ti->files().file_size(i) > 0
						? int(file_progress[idx] * 1000 / ti->files().file_size(i)) : 1000;
					assert(file_progress[idx] <= ti->files().file_size(i));

					bool const complete = file_progress[idx] == ti->files().file_size(i);

					std::string title{ti->files().file_name(i)};
					if (!complete)
					{
						std::snprintf(str, sizeof(str), " (%.1f%%)", progress / 10.0);
						title += str;
					}

					if (f != file_status.end() && f->file_index == i)
					{
						title += " [ ";
						if ((f->open_mode & lt::file_open_mode::rw_mask) == lt::file_open_mode::read_write) title += "read/write ";
						else if ((f->open_mode & lt::file_open_mode::rw_mask) == lt::file_open_mode::read_only) title += "read ";
						else if ((f->open_mode & lt::file_open_mode::rw_mask) == lt::file_open_mode::write_only) title += "write ";
						if (f->open_mode & lt::file_open_mode::random_access) title += "random_access ";
						if (f->open_mode & lt::file_open_mode::sparse) title += "sparse ";
						title += "]";
						++f;
					}

					const int file_progress_width = pad_file ? 10 : 65;

					// do we need to line-break?
					if (p + file_progress_width + 13 > terminal_width)
					{
						out += "\x1b[K\n";
						pos += 1;
						p = 0;
					}

					std::snprintf(str, sizeof(str), "%s %7s p: %d ",
						progress_bar(progress, file_progress_width
							, pad_file ? col_blue
							: complete ? col_green : col_yellow
							, '-', '#', title.c_str()).c_str()
						, add_suffix(file_progress[idx]).c_str()
						, static_cast<std::uint8_t>(file_prio[idx]));

					p += file_progress_width + 13;
					out += str;
				}

				if (p != 0)
				{
					out += "\x1b[K\n";
					pos += 1;
				}
			}
		}

		if (print_log)
		{
			for (auto const& e : events)
			{
				if (pos + 1 >= terminal_height) break;
				out += e;
				out += "\x1b[K\n";
				pos += 1;
			}
		}

		// clear rest of screen
		out += "\x1b[J";
		print(out.c_str());

		std::fflush(stdout);

		if (!monitor_dir.empty() && next_dir_scan < now)
		{
			scan_dir(monitor_dir, ses);
			next_dir_scan = now + seconds(poll_interval);
		}
	}

	resume_data_loader.join();

	ses.pause();
	std::printf("saving resume data\n");

	// get all the torrent handles that we need to save resume data for
	std::vector<torrent_status> const temp = ses.get_torrent_status(
		[](torrent_status const& st)
		{
			return st.handle.is_valid() && st.has_metadata && st.need_save_resume;
		}, {});

	int idx = 0;
	for (auto const& st : temp)
	{
		// save_resume_data will generate an alert when it's done
		st.handle.save_resume_data(torrent_handle::save_info_dict);
		++num_outstanding_resume_data;
		++idx;
		if ((idx % 32) == 0)
		{
			std::printf("\r%d  ", num_outstanding_resume_data);
			pop_alerts(view, ses_view, ses, events);
		}
	}
	std::printf("\nwaiting for resume data [%d]\n", num_outstanding_resume_data);

	while (num_outstanding_resume_data > 0)
	{
		alert const* a = ses.wait_for_alert(seconds(10));
		if (a == nullptr) continue;
		pop_alerts(view, ses_view, ses, events);
	}

	if (g_log_file) std::fclose(g_log_file);

	// we're just saving the DHT state
#ifndef TORRENT_DISABLE_DHT
	std::printf("\nsaving session state\n");
	{
		std::vector<char> out = write_session_params_buf(ses.session_state(lt::session::save_dht_state));
		save_file(".ses_state", out);
	}
#endif

	std::printf("closing session\n");

	return 0;
}

